In Vivo and In Vitro Evaluatioon of the Inhibitory Effect of some Medicinal Plant Extracts on Haemozoin Cancentration

Abstract

The resistance of current drugs against malaria parasite is increasing, thus the need for evaluation of the haemozoin (HZ) concentration in malaria parasite as a novel strategy for malaria control. Haemozoin load in the blood of patients was measured after taking antimalarials or plants extracts. The tested plant extracts were established to reduce HZ concentration in vivo. Haemozoin was extracted from the blood samples of all the malaria positive patients studied by centrifugation and the concentration analyzed spectrophotometrically at 400 nm wavelength. Comparative anti-malaria activity of some conventional drugs: Maldox, Halfan, Artecxin, Amatem, Mefloquine (quinolines) and Malmed, the leaf and stem back extracts of Sarcocephalius latifolius and Alstonia boonei, containing potent pyhytochemicals including tannins, flavonoids, saponins, alkaloids, was evaluated to establish the most effective agent for haemozoin reduction and subsequently, malaria therapy. Each agent was administered to patients in each malaria episode, and the absorbance of haemozoin produced determined at 4000 nm wavelength. Packed cell volume (PCV) was estimated to establish the proportion of red blood cells before and after haemozoin production, using microhaematocrit reader. All the chemical antimalarial drugs used effected reduction in haemozoin concentration. However, Mefloquine (Quinolines) showed the highest activity with significant difference of 0.01 (p<0.05). The plant extracts similarly exerted significant reduction in the haemozoin concentration. Nevertheless, Alstonia boonei extract was the most effective in haemozoin reduction at 0.00 significant level (p<0.05). Of all the therapeutants (chemical and plant extracts) tested, Alstonia boonei stem back extract most significantly reduced haemozoin production (p<0.05), indicating its potential for use in novel anti-plasmodium and antimalaria drug formulation.

Keywords: Haemozoin, Antimalarial agents, Haemoglobin degradation, Plasmodium falciparum